Last-ditch efforts to thwart a war in Ukraine could have just hours to succeed as Boris Johnson and Joe Biden warned of a “crucial window for diplomacy” tonight.
The final warning to Vladimir Putin came as it emerged Russia can order multiple attacks across Ukraine’s borders - including strikes on the capital, Kyiv.
Tens of thousands of Russian forces are poised at “multiple points” on Ukraine’s frontiers.
The Prime Minister and US President spent 40 minutes discussing the deepening crisis tonight as the drumbeat to war grew louder.
During the transatlantic call, Mr Johnson and Mr Biden “agreed there remained a crucial window for diplomacy and for Russia to step back from its threats towards Ukraine”, Downing Street said.
A spokeswoman added: “The leaders emphasised that any further incursion into Ukraine would result in a protracted crisis for Russia, with far reaching damage for both Russia and the world.
“They agreed that western allies must remain united in the face of Russian threats, including imposing a significant package of sanctions should Russian aggression escalate.”
The pair also underlined “the need for European countries to reduce their dependence on Russian gas, a move which, more than any other, would strike at the heart of Russia’s strategic interests”.
The PM is due to chair a crunch meeting of the Cobra Whitehall emergency committee tomorrow.
Sixty-per-cent of Russia’s available army is in place for an invasion, with 100 Battalion Tactical Groups in striking distance.
It is feared a “multiple points” storming over the frontiers is being considered - and that half of Putin’s warplanes are ready to attack.
One document seen by the Mirror reveals: “We would expect multiple sequenced axes not a single strike.
“Potential sudden thrust against Kyiv, using precision strikes.”
Speaking in Scotland, Mr Johnson warned the "evidence is pretty clear" Russia is planning an invasion.
He added: "This is a very, very dangerous, difficult situation, we are on the edge of a precipice but there is still time for President Putin to step back."
The PM was due to spend tonight in Cumbria but cut short his trip to return to London for a briefing with spy chiefs.
Foreign Secretary Liz Truss, meanwhile, hosted an emergency Cobra meeting as the crisis deepened.
Defence Minister James Heappey feared missiles and bombs could be landing on Ukrainian cities minutes after the order to invade.
"This isn't a warning about something that could happen in three months' time, this isn't a warning that will be followed by further warnings because greater imminence has been reached,” he said.
"This is a warning because minutes after Putin gives the order, missiles and bombs could be landing on Ukrainian cities, and that means British citizens should leave now whilst they have the opportunities to do so."
Commons Defence Select Committee chairman Tobias Ellwood warned the threat of an invasion was “our Cuban missile crisis”, referring to the 1962 standoff between the US and Soviet Union which took the superpowers to the brink of war.
Global markets were thrown into turmoil as international tension mounted - wiping more than £54billion from the value of the London stock exchange's top 350 companies after markets opened today.
The FTSE100 was trading down more than 2% - plunging to its lowest point in two weeks.
The biggest stock indexes in Germany and France fell by 3.5%.
Financial analyst Danni Hewson, of investment platform AJ Bell, said: "The prospect of war is rarely good for stock markets.”
Downing Street signalled MPs could be hauled back from their week off if Russia invades.
Demands have been growing for Parliament to be recalled from the February half-term recess if Russian forces cross the border.
The PM's spokesman said: "In that situation you would expect that the Prime Minister would want Parliament to be updated and for it to have its say."
Speaking in Sunderland, Labour leader Keir Starmer said: "I think it's very important that Parliament is recalled if there is an invasion.
"I'm sure the Government would do that anyway, because we must have a swift and strong response, a united response, from the United Kingdom and a united response with our allies."
He called for tougher sanctions against Russia, adding: “I'd like that threat to be very real because let's see this for what it is - it's Russian aggression.”
As the countdown to war accelerated, Russian TV whipped up hysteria - highlighting a pro-Moscow Donbas fighter claiming Ukrainian nationalists will “kill and butcher you all, and hang your children on wires”.
The shocking coverage was broadcast as Moscow moved military assets towards Ukraine and conducted war games in Belarus and around Russia.
Social media videos showed tank drills in Leningrad region, with equipment on the move close to Ukraine’s borders in what is thought to be the biggest Russian military build-up since the Second World War.
Western analysts have repeatedly claimed Russia could stage a “false flag” pretext for war - and TV channels alleged Kyiv was poised to attack the Donbas in eastern Ukraine.
One channel showed a fighter from the separatist region saying Ukrainians had threatened to “come and kill and butcher you all, and hang your children on wires, like fascists”.
Anchorman Dmitry Kiselyov - dubbed Putin’s propagandist-in-chief - warned "thousands of civilians have been tortured and savagely killed" in the Donbas and accused the West of "stubbornly ignoring the crimes of the Kyiv regime”.
Russian tanks on invasion drills had to be dug out of the mud after getting stuck.
The armoured column sank in a quagmire in the Rostov region, bordering Ukraine.
Overnight Sunday to Monday, an RAF C-17 Globemaster plane flew from RAF Brize Norton, Oxfordshire, to Kyiv during darkness, returning before dawn.
The secret mission could have been to evacuate sensitive material from the UK’s Kyiv embassy.
Two American B52 bombers flew from RAF Mildenhall, Suffolk, to the Mediterranean.
One flew close to Tartous, Syria, where Russia has a significant naval base.
